P0132 Ho2S Circuit High Voltage Bank 1 Sensor 1 - Isuzu 2000 Trooper Workshop Manual

6E–172
TROOPER 6VE1 3.5L ENGINE DRIVEABILITY AND EMISSIONS

P0132 HO2S Circuit High Voltage Bank 1 Sensor 1

Circuit Description
The powertrain control module (PCM) supplies a bias
voltage of about 450 mV between the heated oxygen
sensor (HO2S) signal and low circuits. When measured
with a 10 megaohm digital voltmeter, this may display as
low as 320 mV. The oxygen sensor varies the voltage
within a range of about 1000 mV when exhaust is rich,
down through about 10 mV when exhaust is lean. The
PCM constantly monitors the HO2S signal during "closed
loop" operation and compensates for a rich or lean
condition by decreasing or increasing injector pulse width
as necessary. If the Bank 1 HO2S 1 voltage remains
excessively high for an extended period of time, DTC
P0132 will be set.
Conditions for Setting the DTC
D No related DTCs.
D Engine coolant temperature is above 60°C (140°F)
D "Closed loop" commanded air/fuel ratio is between
14.5 and 14.8.
D Throttle angle is between 3% and 19%.
D Bank 1 HO2S 1 signal voltage remains above 952 mV
during normal "closed loop" operation for a total of 77
seconds over a 90-second period.
OR
D Bank 1 HO2S 1 signal voltage remains above 500 mV
during "deceleration fuel cutoff mode" operation for 3
seconds.
Diagnostic Trouble Code (DTC)
Action Taken When the DTC Sets
D The PCM will illuminate the malfunction indicator lamp
(MIL) the first time the fault is detected.
D The PCM will store conditions which were present
when the DTC was set as Freeze Frame and in the
Failure Records data.
D "Open loop" fuel control will be in effect.
Conditions for Clearing the MIL/DTC
D The PCM will turn the MIL "OFF" on the third
consecutive trip cycle during which the diagnostic has
been run and the fault condition is no longer present.
D A history DTC P0132 will clear after 40 consecutive
warm-up cycles have occurred without a fault.
D DTC P0132 can be cleared by using the Tech 2 "Clear
Info" function or by disconnecting the PCM battery
feed.
Diagnostic Aids
Check the following items:
D Fuel pressure – The system will go rich if pressure is
too high. The PCM can compensate for some
increase. However, if fuel pressure is too high, a DTC
P0132 may be set. Refer to Fuel System Diagnosis .
D Perform "Injector Balance Test" – Refer to Fuel System
Diagnosis .
D Check the EVAP canister for fuel saturation – If full of
fuel, check canister control and hoses.
Evaporative (EVAP) Emission Control System .
D06RY00170
Refer to